Just behind wheat and rice, maize is the third most important grain crop in world, grown many agricultural areas. In Mozambique, rainfall declining, posing serious threats to national food sovereignty security, particularly southern regions of country. Despite this fact, few research studies have been conducted on performance Mozambique´s germplasm under drought stress conditions. A randomized ...

Each quantum of light absorbed by a chlorophyll molecule rises an electron from the ground state to an excited state. Upon de-excitation from a chlorophyll a molecule from excited state 1 to ground state, a small proportion (3-5% in vivo) of the excitation energy is dissipated as red fluorescence. The indicator function of chlorophyll fluorescence arises from the fact that fluorescence emission...

From the absorption spectra and the excitation spectra of chlorophyll a fluorescence measured (4-77 °K) at different wavelengths (685-760 nm) and their comparison with the emission spectra published elsewhere 23, we confirm that both the Pigment Systems (I and II) contain chlorophyll b, chlorophyll a 670 and chlorophyll a 678. But System II is relatively enriched in chlorophyll b and System I i...

The principles, equipment and procedures for measuring leaf and canopy gas exchange have been described previously as has chlorophyll fluorescence. Simultaneous measurement of the responses of leaf gas exchange and modulated chlorophyll fluorescence to light and CO2 concentration now provide a means to determine a wide range of key biochemical and biophysical limitations on photo synthesis in v...

When the sub-core complex of photosystem II, D1/D2, is irradiated at 436 or 415 nm (absorption by chlorophyll and pheophytin and ß-carotene) or 540 nm (absorption primarily by pheophytin), the low temperature fluorescence spectrum has two maxima, at 685 and 674 nm. This shows the existence of at least two different fluorescent forms of chlorophyll (chlorophyll a and perhaps pheophytin a). When ...

Passive steady-state chlorophyll fluorescence (Fs) provides a direct diagnosis of the functional status of vegetation photosynthesis. With the prospect of mapping Fs using remote sensing techniques, field measurements are mandatory to understand to which extent Fs allows detecting plant stress in different environments. Trees of four common species in Valencia were classified in either a low or...